淡水鱼塘水体污染的主成分分析

Principal Component Analysis of Pollution in Freshwater Fish Ponds

目前淡水鱼塘水质评价中将重金属、富营养化和有机污染分开独立研究的较多,同时综合起来进行评价分析的较少。为了解淡水混养鱼塘水体综合污染的特征和发生机理,用基于主成分的因子分析法对2011—2013年养殖周期内南宁武鸣区3口淡水鱼塘中高锰酸盐指数、铵态氮、亚硝酸态氮、总磷、总氮、Cu、Zn等7个指标的监测数据进行了分析。分析结果表明,目前武鸣淡水鱼塘水质主要存在两类污染,主要受第一主成分"重金属+总氮"复合污染中的Zn、Cu和总氮的相互作用控制,其次受控于还原性"有机物+无机氮"污染中的高锰酸盐指数、亚硝酸态氮和铵态氮的共同影响。"重金属+总氮"复合污染是武鸣淡水鱼塘水质的主要特征,Zn、Cu和总氮是最重要的影响因子。总氮与重金属Zn、Cu密切负相关,总氮与Zn、Cu之间存在拮抗作用,鱼塘水体氮失衡导致的富营养化可能降低了重金属Zn、Cu污染的严重性。

At present,there are few combined analysis of heavy metals,eutrophication and organic pollution in the water quality in freshwater fish ponds,even though there were many separate researches on heavy metals,eutrophication and organic pollution.The contents of total nitrogen（TN）,total phosphorus（TP）,chemical oxygen demand（CODMn）,ammonia nitrogen（NH4＋-N）,nitrite nitrogen（NO2--N）,copper（Cu）,and zinc（Zn）were routinely monitored in the water for three consecutive years from 2011to2013 to investigate the characteristics of water pollution and occurrence mechanism in freshwater polyculture ponds by factor analysis method based on principal component.The results showed that there were two types of water environmental pollution in fresh water ponds in Wu Ming,Zn,Cu and total nitrogen of＂heavy metal and total nitrogen＂pollution and permanganate index,nitrite nitrogen and ammonium nitrogen of＂organic and inorganic nitrogen＂pollution.The major feature about the quality of freshwater fish pond in Wu Ming was of water heavy metal and total nitrogen compound pollution,with the most important factors of Zn and Cu and total nitrogen.There was a close relationship between total nitrogen and heavy metals Zn and Cu,and the antagonistic effect was found between the total nitrogen and Zn and Cu in the fish ponds.The heavy metal Zn and Cu pollution was attributed to the nitrogen imbalance caused by eutrophication.